1 // Copyright 2002 Adam Megacz, see the COPYING file for licensing [GPL]
7 /** a block of Forth bytecode */
8 class ForthBlock implements OpCodes, Tokens {
12 int[] op = new int[10];
13 Object[] arg = new Object[10];
16 public ForthBlock(int line, String sourceName) { this.line = line; this.sourceName = sourceName; }
17 public ForthBlock(int line, String sourceName, int op_, Object arg_) { this(line, sourceName); add(op_, arg_); }
19 public int size() { return size; }
20 public void set(int pos, int op_, Object arg_) { op[pos] = op_; arg[pos] = arg_; }
21 public void paste(ForthBlock other) { for(int i=0; i<other.size; i++) add(other.op[i], other.arg[i]); }
22 public ForthBlock add(int op_) { return add(op_, null); }
23 public ForthBlock add(int op_, Object arg_) {
24 if (size == op.length - 1) {
25 int[] op2 = new int[op.length * 2]; System.arraycopy(op, 0, op2, 0, op.length); op = op2;
26 Object[] arg2 = new Object[op.length * 2]; System.arraycopy(arg, 0, arg2, 0, arg.length); arg = arg2;
34 public Object eval(final JS.Scope s) throws ControlTransferException, JS.Exn { return eval(s, new Stack()); }
35 public Object eval(final JS.Scope s, Stack t) throws ControlTransferException {
36 for(int i=0; i<size; i++)
38 case LABEL: break; // FIXME
39 case LITERAL: t.push(arg[i]); break;
40 case OBJECT: t.push(new JS.Obj()); break;
41 case ARRAY: t.push(new JS.Array(JS.toNumber(arg[i]).intValue())); break;
42 case DECLARE: s.declare((String)t.pop()); break;
43 case THIS: t.push(s); break; // FIXME: transparents
44 case JT: if (JS.toBoolean(t.pop())) i += JS.toNumber(arg[i]).intValue() - 1; break;
45 case JF: if (!JS.toBoolean(t.pop())) i += JS.toNumber(arg[i]).intValue() - 1; break;
46 case JMP: i += JS.toNumber(arg[i]).intValue() - 1; break;
47 case POP: t.pop(); break;
48 case SWAP: t.swap(); break;
49 case DUP: t.push(t.peek()); break;
51 case EXPR: t.push(((ForthBlock)arg[i]).eval(s)); break;
52 case SCOPE: t.push(((ForthBlock)arg[i]).eval(new JS.Scope(s))); break;
54 case ASSERT: if (!JS.toBoolean(t.pop())) throw new EvaluatorException(line, sourceName, "assertion failed"); break;
55 case RETURN: throw new ReturnException(t.pop());
56 case THROW: throw new JS.Exn(t.pop());
59 case INSTANCEOF: break;
63 Object[] keys = ((JS)o).keys();
64 JS.Array a = new JS.Array();
65 a.setSize(keys.length);
66 for(int j=0; j<keys.length; j++) a.setElementAt(keys[j], j);
71 case Lexer.BITNOT: t.push(new Long(~JS.toLong(t.pop()))); break;
72 case Lexer.BANG: t.push(new Boolean(!JS.toBoolean(t.pop()))); break;
75 // FIXME: make sure this can only appear in proper places
78 case Lexer.CONTINUE: {
79 // FIXME: make sure this can only appear in proper places
83 ForthBlock loop = (ForthBlock)arg[i];
84 Stack t2 = new Stack();
85 t2.push(Boolean.TRUE);
89 result = (Boolean)loop.eval(new JS.Scope(s), t2);
90 } catch (ContinueException c) {
91 result = Boolean.TRUE;
92 } catch (BreakException b) {
93 result = Boolean.FALSE;
95 if (result == Boolean.FALSE) break;
97 t2.push(Boolean.FALSE);
103 Object val = t.pop();
104 Object key = t.pop();
105 JS target = (JS)t.peek();
106 if (target == null) throw new JS.Exn("tried to put a value to the " + key + " property on the null value");
107 target.put(key, val);
128 JS.Array arguments = new JS.Array();
129 int numArgs = JS.toNumber(arg[i]).intValue();
130 arguments.setSize(numArgs);
131 for(int j=numArgs - 1; j >= 0; j--) arguments.setElementAt(t.pop(), j);
132 JS.Function f = (JS.Function)t.pop();
133 if (f == null) throw new JS.Exn(new EvaluatorException(line, sourceName, "attempted to call null"));
134 t.push(f.call(arguments));
138 case OpCodes.FUNCTION: {
139 final ForthBlock myBytes = (ForthBlock)arg[i];
140 t.push(new JS.Function() {
141 public String toString() { return sourceName + ":" + line; }
142 public String getSourceName() throws JS.Exn { return sourceName; }
143 public int getLine() throws JS.Exn { return line; }
144 public Object _call(final JS.Array args) throws JS.Exn {
145 Function save = JS.getCurrentFunction();
146 JS.currentFunction.put(java.lang.Thread.currentThread(), this);
147 JS.Scope scope = new JS.Scope(s) {
149 public String getSourceName() { return sourceName; }
150 public Object get(Object key) throws JS.Exn {
151 if (key.equals("trapee")) return org.xwt.Trap.currentTrapee();
152 else if (key.equals("cascade")) return org.xwt.Trap.cascadeFunction;
153 return super.get(key);
156 Stack t0 = new Stack();
159 return myBytes.eval(scope, t0);
160 } catch (ReturnException r) {
162 } catch (ControlTransferException c) {
163 throw new EvaluatorException(line, sourceName, "error, ControlTransferException tried to leave a function: " + c);
165 if (save == null) JS.currentFunction.remove(java.lang.Thread.currentThread());
166 else JS.currentFunction.put(java.lang.Thread.currentThread(), save);
173 case Lexer.INC: case Lexer.DEC: {
174 boolean isPrefix = JS.toBoolean(arg[i]);
175 Object key = t.pop();
176 JS obj = (JS)t.pop();
177 Number num = JS.toNumber(obj.get(key));
178 Number val = new Double(op[i] == Lexer.INC ? num.doubleValue() + 1.0 : num.doubleValue() - 1.0);
180 t.push(isPrefix ? val : num);
185 Object right = t.pop();
186 Object left = t.pop();
189 case Lexer.BITOR: t.push(new Long(JS.toLong(left) | JS.toLong(right))); break;
190 case Lexer.BITXOR: t.push(new Long(JS.toLong(left) ^ JS.toLong(right))); break;
191 case Lexer.BITAND: t.push(new Long(JS.toLong(left) & JS.toLong(right))); break;
196 if (l instanceof String || r instanceof String) {
197 if (l == null) l = "null";
198 if (r == null) r = "null";
199 if (l instanceof Number && ((Number)l).doubleValue() == ((Number)l).longValue())
200 l = new Long(((Number)l).longValue());
201 if (r instanceof Number && ((Number)r).doubleValue() == ((Number)r).longValue())
202 r = new Long(((Number)r).longValue());
203 t.push(l.toString() + r.toString()); break;
205 t.push(new Double(JS.toDouble(l) + JS.toDouble(r))); break;
208 case Lexer.SUB: t.push(new Double(JS.toDouble(left) - JS.toDouble(right))); break;
209 case Lexer.MUL: t.push(new Double(JS.toDouble(left) * JS.toDouble(right))); break;
210 case Lexer.DIV: t.push(new Double(JS.toDouble(left) / JS.toDouble(right))); break;
211 case Lexer.MOD: t.push(new Double(JS.toDouble(left) % JS.toDouble(right))); break;
213 case Lexer.LSH: t.push(new Long(JS.toLong(left) << JS.toLong(right))); break;
214 case Lexer.RSH: t.push(new Long(JS.toLong(left) >> JS.toLong(right))); break;
215 case Lexer.URSH: t.push(new Long(JS.toLong(left) >>> JS.toLong(right))); break;
217 // FIXME: these need to work on strings
218 case Lexer.LT: t.push(JS.toDouble(left) < JS.toDouble(right) ? Boolean.TRUE : Boolean.FALSE); break;
219 case Lexer.LE: t.push(JS.toDouble(left) <= JS.toDouble(right) ? Boolean.TRUE : Boolean.FALSE); break;
220 case Lexer.GT: t.push(JS.toDouble(left) > JS.toDouble(right) ? Boolean.TRUE : Boolean.FALSE); break;
221 case Lexer.GE: t.push(JS.toDouble(left) >= JS.toDouble(right) ? Boolean.TRUE : Boolean.FALSE); break;
225 // FIXME: should use Javascript coercion-equality rules
229 if (l == null) { Object tmp = r; r = l; l = tmp; }
230 if (l == null && r == null) ret = true;
231 else if (l instanceof Boolean) ret = new Boolean(JS.toBoolean(r)).equals(l);
232 else if (l instanceof Number) ret = JS.toNumber(r).doubleValue() == JS.toNumber(l).doubleValue();
233 else if (l instanceof String) ret = r != null && l.equals(r.toString());
234 else ret = l.equals(r);
235 t.push(new Boolean(op[i] == Lexer.EQ ? ret : !ret)); break;
238 default: throw new Error("unknown opcode " + op[i]);
242 for(int i=0; i<size; i++) {
243 System.out.println((op[i] >= 0 ? codeToString[op[i]] : "" + op[i]) + " [" + arg[i] + "]");
245 throw new EvaluatorException(line, sourceName, "eval() terminated with " + t.size() + " elements on the stack; one expected");
250 public Object doGet(final Object o, final Object v) {
252 throw new EvaluatorException(line, sourceName, "tried to get property \"" + v + "\" from the null value");
254 if (o instanceof String) {
255 if (v.equals("length")) return new Integer(((String)o).length());
256 else if (v.equals("substring")) return new JS.Function() {
257 public Object _call(JS.Array args) {
258 if (args.length() == 1) return ((String)o).substring(JS.toNumber(args.elementAt(0)).intValue());
259 else if (args.length() == 2) return ((String)o).substring(JS.toNumber(args.elementAt(0)).intValue(),
260 JS.toNumber(args.elementAt(1)).intValue());
261 else throw new Error("String.substring() can only take one or two arguments");
264 else if (v.equals("toLowerCase")) return new JS.Function() {
265 public Object _call(JS.Array args) {
266 return ((String)o).toLowerCase();
268 else if (v.equals("toUpperCase")) return new JS.Function() {
269 public Object _call(JS.Array args) {
270 return ((String)o).toString().toUpperCase();
272 else if (v.equals("charAt")) return new JS.Function() {
273 public Object _call(JS.Array args) {
274 return ((String)o).charAt(JS.toNumber(args.elementAt(0)).intValue()) + "";
276 else if (v.equals("lastIndexOf")) return new JS.Function() {
277 public Object _call(JS.Array args) {
278 if (args.length() != 1) return null;
279 return new Integer(((String)o).lastIndexOf(args.elementAt(0).toString()));
281 else if (v.equals("indexOf")) return new JS.Function() {
282 public Object _call(JS.Array args) {
283 if (args.length() != 1) return null;
284 return new Integer(((String)o).indexOf(args.elementAt(0).toString()));
286 throw new Error("Not Implemented: propery " + v + " on String objects");
287 } else if (o instanceof Boolean) {
288 throw new Error("Not Implemented: properties on Boolean objects");
289 } else if (o instanceof Number) {
290 Log.log(this, "Not Implemented: properties on Number objects");
292 //throw new Error("Not Implemented: properties on Number objects");
293 } else if (o instanceof JS) {
294 return ((JS)o).get(v);
300 public Object[] os = new Object[256];
301 private int size = 0;
302 public void push(Object o) { os[size++] = o; }
303 public Object pop() { return os[--size]; }
304 public Object peek() { return os[size - 1]; }
305 public void swap() { Object temp = os[size - 1]; os[size - 1] = os[size - 2]; os[size - 2] = temp; }
306 public int size() { return size; }
309 static class EvaluatorException extends RuntimeException {
310 public EvaluatorException(int line, String sourceName, String s) { super(sourceName + ":" + line + " " + s); }
313 static abstract class ControlTransferException extends Exception { }
314 static class BreakException extends ControlTransferException {
316 BreakException(String label) { this.label = label; }
318 static class ContinueException extends ControlTransferException {
320 ContinueException(String label) { this.label = label; }
322 static class ReturnException extends ControlTransferException {
323 public Object retval;
324 ReturnException(Object retval) { this.retval = retval; }